Make it possible to pass command line options through to scripts.

The feature is documented with the zeek_script_args variable in
init-bare.zeek.

scripts/base/init-bare.zeek

@@ -454,6 +454,18 @@ type connection: record {
 	inner_vlan: int &optional;
 };
 
+## Arguments given to Zeek from the command line. In order to use this, Zeek
+## must use the "--" command line argument, then give the script name immediately
+## after the double hyphens and the provide the arguments after that. For example:
+## 
+##   zeek --bare-mode -- myscript.zeek -a -b -c
+## 
+## To use Zeek as an executable interpreter, include a line at the top of a script
+## like the following and make the script executable:
+## 
+##   #!/usr/local/zeek/bin/zeek -- 
+const zeek_script_args: vector of string = vector();
+
 ## Default amount of time a file can be inactive before the file analysis
 ## gives up and discards any internal state related to the file.
 option default_file_timeout_interval: interval = 2 mins;

src/NetVar.cc

@@ -30,6 +30,8 @@ zeek::VectorType* index_vec;
 zeek::VectorType* mime_matches;
 zeek::RecordType* mime_match;
 
+zeek::VectorVal* zeek_script_args;
+
 zeek::RecordType* socks_address;
 
 zeek::TableVal* tcp_reassembler_ports_orig;

src/Options.cc

@@ -5,6 +5,7 @@
 #include "Options.h"
 
 #include <algorithm>
+#include <sstream>
 
 #include <unistd.h>
 
@@ -186,10 +187,50 @@ Options parse_cmdline(int argc, char** argv)
 		}
 	else
 		{
-		for ( auto i = 0; i < argc; ++i )
+		if ( argc > 1 )
+			{
+			auto endsWith = [](const std::string& str, const std::string& suffix)
+				{
+				return str.size() >= suffix.size() && 0 == str.compare(str.size()-suffix.size(), suffix.size(), suffix);
+				};
+
+			auto i = 0;
+			for ( ; i < argc && ! endsWith(argv[i], "--"); ++i )
+				{
 				zeek_args.emplace_back(argv[i]);
 				}
 
+			// If a script is invoked with Zeek as the interpreter, the arguments provided
+			// directly in the interpreter line of the script won't be broken apart in the 
+			// argv on Linux so we split it up here.
+			if ( endsWith(argv[i], "--") && zeek_args.size() == 1 )
+				{
+				std::istringstream iss(argv[i]);
+				for ( std::string s; iss >> s; )
+					{
+					if ( ! endsWith(s, "--") )
+						{
+						zeek_args.emplace_back(s);
+						}
+					}
+				}
+
+			if ( i < argc )
+				{
+				// There is an additional increment here to skip over the "--" if it was found.
+				if ( endsWith(argv[i], "--") )
+					++i;
+
+				// The first argument after the double hyphens in implicitly a script name.
+				rval.scripts_to_load.emplace_back(argv[i++]);
+
+				// If there are more argument, grab them for script arguments
+				for ( ; i < argc; ++i )
+					rval.script_args.emplace_back(argv[i]);
+				}
+			}
+		}
+
 	constexpr struct option long_opts[] = {
 		{"parse-only",	no_argument,		nullptr,	'a'},
 		{"bare-mode",	no_argument,		nullptr,	'b'},

src/Options.h

@@ -74,6 +74,8 @@ struct Options {
 	std::set<std::string> plugins_to_load;
 	std::vector<std::string> scripts_to_load;
 	std::vector<std::string> script_options_to_set;
+
+	std::vector<std::string> script_args;
 };
 
 /**

src/zeek-setup.cc

@@ -660,6 +660,16 @@ SetupResult setup(int argc, char** argv, Options* zopts)
 	init_net_var();
 	run_bif_initializers();
 
+	// Assign the script_args for command line processing in Zeek scripts.
+	if ( ! options.script_args.empty() )
+		{
+		auto script_args_val = zeek::id::find_val("zeek_script_args")->AsVectorVal();
+		for ( const string& script_arg: options.script_args )
+			{
+			script_args_val->Assign(script_args_val->Size(), zeek::make_intrusive<zeek::StringVal>(script_arg));
+			}
+		}
+
 	// Must come after plugin activation (and also after hash
 	// initialization).
 	binpac::FlowBuffer::Policy flowbuffer_policy;